1. Technical Field
The present invention relates to lane departure warning and avoidance systems, and, more particularly, to a lane departure warning and avoidance system configured to automatically reduce or suppress the warning threshold, or otherwise modify the warning algorithm, at predefined conditions.
2. Background Art
Lane departure warning and avoidance (LDW) systems have been developed to aid the orderly navigation of thoroughfares by vehicle operators. More particularly, safety systems assist operators in maintaining proper lane alignment by alerting the operator to a possible un-intentional lane departure. Unlike, scarifications commonly found on thoroughfare shoulders that alert the operator of an at least partially completed lane departure, LDW systems provide timely warnings prior to lane departure. These LDW systems typically utilize at least one camera/image processor or other type of sensor (e.g., IR) to detect the lane markings that delineate the lane boundaries. Other lateral support systems, such as lane keeping (LK) systems, have similarly been developed.
One of the factors used for robust lane marking identification is the preview length of the lane markings ahead of the vehicle. Due to the curvature of some thoroughfare curves, however, the cameras of these systems are often unable to view the approaching lane marking for a sufficient period (mainly due to limited camera field of view (FOV)). Thus, the lane sensing capability of these conventional systems deteriorate directly proportional to the radius of curvature. As a result, the LDW system may have difficulties in providing timely warnings on sharp curves, especially at high speeds.
Of further concern, these conventional systems do not provide means for detecting purposeful lane departures, and therefore, often result in false or annoyance alarms that may distract the operator during an intricate maneuver. In other words, these systems are unable to discern whether the operator is currently in control of the vehicle, and intends to leave the lane. Finally, these systems also do not provide for calibration means, or performance measuring. As such, these systems may further provide false (annoyance) alarms and missed detections due to the natural performance degradation of the image processor and/or camera.